#is等于   is not不等于
a=[1,2]
b=a
print(a is b)
print(a is not b)
print('-------')
#!=不等于
a='xuzehui'
b!=a
print(a is b)
print(a is not b)
print('-------')
#in包含于   not in不包含于
x='help'
print('p'in x)
print('p' not in  x)